[modules] Don't force context allocation of variables declared in module scope.

src/ast/scopes.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_AST_SCOPES_H_
 #define V8_AST_SCOPES_H_
 
 #include "src/ast/ast.h"
 #include "src/base/hashmap.h"
 #include "src/globals.h"
@@ skipping 313 matching lines @@
   // Is this scope inside a with statement.
   bool inside_with() const { return scope_inside_with_; }
 
   // Does this scope access "super" property (super.foo).
   bool uses_super_property() const { return scope_uses_super_property_; }
   // Does this scope have the potential to execute declarations non-linearly?
   bool is_nonlinear() const { return scope_nonlinear_; }
 
   // Whether this needs to be represented by a runtime context.
   bool NeedsContext() const {
-    // Catch and module scopes always have heap slots.
+    // Catch scopes always have heap slots.
     DCHECK(!is_catch_scope() || num_heap_slots() > 0);
-    DCHECK(!is_module_scope() || num_heap_slots() > 0);
-    return is_with_scope() || num_heap_slots() > 0;
+    return num_heap_slots() > 0;
   }
 
   // ---------------------------------------------------------------------------
   // Accessors.
 
   // The type of this scope.
   ScopeType scope_type() const { return scope_type_; }
 
   // The language mode of this scope.
   LanguageMode language_mode() const { return language_mode_; }
@@ skipping 549 matching lines @@
   // Convenience variable; Subclass constructor only
   Variable* this_function_;
   // Module descriptor; module scopes only.
   ModuleDescriptor* module_descriptor_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_SCOPES_H_